Enthalpies for the transfer of various globular proteins from dilute buffer to aqueous alcohol solutions will be obtained for low concentrations of the cosolute. Enthalpies of transfer of N-acetylated amino acids, their amides and other model substances from dilute buffer to the aqueous alcohol will be used to determine the enthalpy of transfer for the completely denatured protein. These data will be used to test the quality of available models of the accessibility of the protein surface to solvent. Enthalpies for the transfer of globular proteins from dilute buffer to aqueous solutions containing trivalent lanthanide ions will be obtained for low concentrations of these ions. Enthalpies of transfer of N-acetylated amino acids, their amides and other model substances will be determined in a similar manner. These model substances will provide an enthalpy of transfer for the completely denatured protein. Amino acid moieties exposed to the solvent and trivalent ions during denaturation will be probed using tunable dye laser spectroscopy.